1. Field of the Invention
The present invention relates to a method for generating a speed control code for a train, and particularly to an improved method for generating a speed control code for a train which is capable of significantly increasing a train transportation capacity and efficiency by enabling a high speed train operation and by maintaining an optimized interval between a preceding train and the next succeeding train.
2. Description of the Conventional Art
Generally, it is very important to control the interval between a preceding train and the next succeeding train for enhancing a train transportation efficiency. In order to prevent a train collision, an off-line train accident, or the like, a traffic system is provided for enabling a high speed operation of the trains.
However, the speed control of the train is generally performed in cooperation with a traffic signal light. In this case, as the technology advances, and the train speed is made faster, there may occur an accident because the train driver still must visually monitor and check the traffic situation by using such signal lights.
In order to prevent the above-mentioned problems and to enhance the transportation efficiency of the train, a train stop apparatus, an automatic speed control apparatus, an automatic train running apparatus or the like is used. Theses apparatuses are directed to transmitting a speed indication code, which indicates the running speed of the next succeeding train and a preceding train based on the distance between the preceding train and the next succeeding train, to a traffic signal light device, so that the speed of the trains can be controlled according to the information from the traffic signal light device.
The conventional speed control signal generation principle for the train will now be explained in more detail with reference to FIG. 1.
A speed code generator 10 detects a preceding train which runs at a position "A", and applies a speed indication code such as an absolute stop code RR, a stop code R, speed limit codes R1 and R2, and the like to each of track intervals L1 through L4, which codes are obtained based on the distance between the preceding train and the next succeeding train which runs at a position "B". If the next succeeding train enters the track interval L2, the next succeeding train receives a speed indication code R which is applied to the track interval L2, and the succeeding train controls its speed based on the distance from the preceding train in accordance with the speed indication code R. In this case, the track interval L1 is a buffer zone for preventing any accident in case that the next succeeding train cannot stop at the track interval L2.
For example, on the assumption that the preceding train runs at the position "A" at a speed of 150 km/h, and the next succeeding train runs at a speed of 200 km/h, the next succeeding train can run at the maximum speed at the position "B" which is within the previous interval of the track interval L4. When the next succeeding train enters the track interval L4 in which the speed of the train is limited at 100 km/h, the train runs at 100 km/h. At this time, if the preceding train runs at a speed of 150 km/h, the distance between the preceding train and the next succeeding train is made longer, so that the next succeeding train can run at 200 km/h through the interval after the track interval L4.
However, in the conventional method, since the speed of the next succeeding train is controlled in accordance with the distance between the preceding train and the next succeeding train, the deceleration and acceleration of the train are repeated, causing inconvenience to passengers of the train. In addition, when the preceding train is accelerated, the distance is made longer from the next succeeding train, so it is impossible to secure a constant train running distance between the trains, and it is impossible to flexibly set the distance of the track interval, thus causing many problems with respect to the on-time operation of the trains.